Chromatin reorganization on DNA is required for transcriptional regulation in eukaryotes. Two chromatin alterations, ribosylation of proteins by PARP and chromatin phosphorylation correlate with increased transcription at heat shock loci in Drosophila following a heat shock response. Our objective is to understand how these processes function in transcriptional regulation of the hsp70 gene in Drosophila melanogaster. To achieve this we will; (1) Probe for proteins responsible for PARP dependent recruitment and ribosylation; (2) Identify kinases and other proteins responsible for chromatin phosphorylation; (3) Determine the spatial and temporal relationship of chromatin ribosylation and phosphorylation to the transcriptional machinery following a heat shock response. These goals will be met using co-immunofluorescence overlap staining of polytene chromosomes, ChIP assays followed by real-time PCR, mutant protein analysis, double immunoprecipitation assays, and drug inhibition of protein activity. Our long-term goal is to form a complete picture of how these chromatin modifications function in protein recruitment and transcriptional regulation and utilize this knowledge to provide targets for drug development to inhibit uncontrolled gene regulation.